JP2013115653A - Imaging apparatus, control method thereof and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous detection of wavelength range selecting means in insertion/detachment thereof when a function to insert/detach the wavelength range selecting means into/from an optical path is included.SOLUTION: When a photometry section 8 recognizes that luminance of a captured image is a specified value or less, a filter control section 9 stops movement detection by a movement detection section 10 and drives a motor 3 so that an infrared cut filter 2a is detached from above an imaging optical path. Thus, erroneous detection of "movement of a subject", which is due to luminance difference caused by movement of a filter frame even though there is no movement in the captured image, can be prevented. In a video signal processing part 6, it is switched to black-and-white output processing, and after a lapse of an operation time to completion of switching of the infrared cut filter 2a, motion detection by the movement detection part 10 is resumed.

Description

  The present invention provides an image pickup apparatus that prevents a movement from being erroneously detected when a wavelength band sorting unit is inserted and removed when the wavelength band sorting unit such as an infrared cut filter has a function of inserting and removing from the optical path. Regarding the program.

  There is a surveillance camera device having a motion detection function. As a motion detection method, for example, there is a method in which a luminance change is determined as a motion using a luminance difference between a plurality of imaging frames having a time difference. However, there is a problem that even when the brightness of the entire captured image changes, such as when the illumination around the subject is turned ON / OFF, it is detected that there is motion. As a countermeasure, a surveillance camera device has been devised in which motion detection is not performed when the overall brightness changes, or motion detection is performed using luminance data corrected for the change in overall brightness. (For example, refer to Patent Document 1).

JP 2001-054004 A

  However, for example, in a surveillance camera device having a function of inserting / removing an infrared cut filter to / from the imaging optical path, the movement of the infrared cut filter or the filter frame that holds the infrared cut filter moves even if the subject does not move. There was a case of false detection.

  The present invention has been made in view of the above points, and in the case of having a function of inserting / removing the wavelength band selecting unit with respect to the optical path, the movement is not erroneously detected when the wavelength band selecting unit is inserted / removed. The purpose is to do.

  An imaging apparatus according to the present invention includes an imaging unit that converts a subject image formed by an imaging optical system into an imaging signal, and a wavelength band that is on an optical path of the imaging optical system and that selects a specific wavelength band from incident light. A selection unit; an insertion / removal unit for inserting / removing the wavelength band selection unit with respect to the optical path; a photometry unit for measuring luminance of a captured image obtained by the imaging unit; and the insertion based on an output of the photometry unit. A control means for controlling the operation of the detaching means; and a motion detecting means for detecting a motion in the captured image obtained by the imaging means, wherein the control means moves the wavelength band selecting means to the optical path by the inserting / removing means. In contrast, during the insertion / removal, the motion detection means is controlled to stop the motion detection.

  According to the present invention, when the wavelength band selecting unit is inserted into and removed from the optical path, the motion detection of the motion detecting unit is stopped, the motion determination criterion of the motion detecting unit is changed, or the motion detection region of the motion detecting unit Thus, it is possible to prevent erroneous detection of movement when the wavelength band selecting means is inserted / removed.

It is a figure which shows the structure of the surveillance camera apparatus which concerns on 1st Embodiment. It is a flowchart of the motion detection stop control at the time of IRCF detachment in the first embodiment. It is a flowchart of the motion detection area | region change control at the time of IRCF detachment | leave in 2nd Embodiment. It is a figure explaining the motion detection area change at the time of IRCF detachment in a 2nd embodiment.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a surveillance camera device that is an imaging device according to a first embodiment of the present invention. In the figure, reference numeral 1 denotes an imaging lens as an imaging optical system. Reference numeral 2 denotes a filter switching unit, which is configured to switch an infrared cut filter 2a (hereinafter referred to as IRCF) that is a wavelength band selection unit and a dummy glass 2b by a motor 3 that is an insertion / removal unit. Normally, the light incident through the imaging lens 1 is incident on the imaging element 4 after the near-infrared light is removed by the IRCF 2a. This is because the imaging device 4 is sensitive to light in the near infrared region (λ = about 700 nm or more), and if the IRCF 2a is not passed, the captured image becomes reddish and the color balance is lost. On the other hand, when the illuminance of the subject is low, the dummy glass 2b is inserted on the imaging optical path (optical axis) instead of the IRCF 2a. The dummy glass 2b corrects that the optical path length is changed by removing the IRCF 2a from the imaging optical path. Reference numeral 2c denotes a surrounding filter frame for fixing and holding the IRCF 2a and the dummy glass 2b.

  Reference numeral 4 denotes an image pickup device as an image pickup means such as a CCD or CMOS, which converts a subject image formed by the image pickup lens 1 into an image pickup signal. Reference numeral 5 denotes an image signal processing unit, which performs noise removal and gain adjustment by correlated double samples on the image signal output from the image sensor 4. A video signal processing unit 6 performs video signal processing such as AD conversion, color conversion processing, white balance correction, gamma processing, inter-pixel interpolation processing, and switches the video signal processing to black and white output processing when the IRCF 2a is removed. This is because, by removing the IRCF 2a, near-infrared light also enters the image sensor 4 and the luminance of the subject increases, but the S / N due to the color signal under low illuminance is suppressed from deteriorating. . A video signal output unit 7 outputs video signals such as NTSC and PAL. When a video signal is transmitted as a digital signal to a network, a compression / encoding function or a network interface function is provided.

  Reference numeral 8 denotes a photometry unit as photometry means, which measures the luminance of the captured image. Reference numeral 9 denotes a filter control unit as control means, which determines whether or not to drive the filter switching unit 2 based on the photometry result of the photometry unit 8 and issues an instruction to the motor 3 and the motion detection unit 10. Reference numeral 10 denotes a motion detection unit serving as a motion detection unit. Based on the luminance component of the captured image in the video signal processing unit 6, the brightness change amount, the change region area ratio, and the change duration in the detection target region Detect if there was any movement. Reference numeral 11 denotes a motion detection processing unit. When a motion is detected by the motion detection unit 10, a predetermined setting such as starting recording, sending a captured image by e-mail, or reproducing an audio file is performed. Perform the process.

  Next, the operation of the monitoring camera device according to the present embodiment will be described. FIG. 2 shows a flowchart of motion detection stop control when the surveillance camera device leaves the IRCF 2a. When the photometry unit 8 recognizes that the brightness of the captured image is equal to or lower than the predetermined value (step S201), after the motion detection by the motion detection unit 10 is stopped (step S202), the filter control unit 9 performs IRCF2a from the imaging optical path. The motor 3 is driven so as to leave (step S203). Conventionally, when it is recognized that the brightness of the captured image is equal to or less than a predetermined value, the IRCF is driven away from the imaging optical path immediately. However, the filter frame moves in the imaging screen from the start of IRCF driving to the completion of driving, and a captured image of a plurality of frames is output during this movement. Since there is a difference in time between adjacent frames, the filter frame is moved, and its position is different. For this reason, even if there is no movement in the captured image, it is erroneously detected that “the subject has moved” due to the luminance difference due to the movement of the filter frame. In the present embodiment, in order to eliminate this erroneous detection, the motion detection by the motion detection unit 10 is first stopped (step S202), and then the IRCF 2a is separated (step S203).

  Next, the video signal processing unit 6 switches to monochrome output processing (step S204). The operation time until the IRCF 2a switching is completed is known in advance, and when this time has elapsed (step S205), the motion detection by the motion detection unit 10 is resumed (step S206). If “with movement” of the subject has been detected immediately before the start of leaving the IRCF 2 a, it is determined that “no movement” only during the leaving of the IRCF 2 a. Therefore, in this case, it is preferable to hold the determination of “with motion” even if the motion detection by the motion detector 10 is stopped.

  As described above, by stopping motion detection when the IRCF 2a is detached, erroneous detection of motion due to movement of the IRCF 2a or the filter frame 2c can be prevented.

  In the present embodiment, the motion detection is controlled to be stopped in step S202. However, instead of stopping, the motion determination reference for motion detection may be changed. The motion detection unit 10 evaluates the luminance change amount, the change area area ratio, and the change duration, and determines the presence or absence of motion. However, the motion determination criterion is changed so as not to react to the change due to the motion of the filter frame 2c. That is why. For example, a portion where the luminance change area in the imaging screen is the same size as the moving area of the IRCF 2a and the filter frame 2c is excluded (outside of the determination criterion). Alternatively, if the moving speed of the luminance change region is the same as the moving speed of the IRCF 2a and the filter frame 2c, it is excluded (excluded from the determination criterion). In the control of stopping the motion detection when leaving the IRCF 2a, it cannot be detected even if there is a movement in a part other than the moving part of the IRCF 2a or the filter frame 2c. However, the IRCF 2a or the filter frame can be controlled by changing the determination criterion. Motion can be detected at portions other than the moving portion 2c.

  In the present embodiment, the control when detaching the IRCF 2a has been described, but the same control is performed when the IRCF 2a is inserted. By controlling in this way, erroneous detection of motion due to the operation of the IRCF 2a and the filter frame 2c when the IRCF 2a is inserted and removed can be eliminated.

(Second Embodiment)
Next, a second embodiment will be described. The configuration of the monitoring camera device is the same as that of the first embodiment, and detailed description thereof is omitted here.
FIG. 3 shows a flowchart of motion detection area change control when the IRCF 2a is detached by the monitoring camera device. When the photometry unit 8 recognizes that the brightness of the captured image is equal to or less than a predetermined value (step S301), the filter control unit 9 drives the motor 3 so as to leave the IRCF 2a from the imaging optical path (step S302).

  In this case, in the motion detection unit 10, even if there is no movement in the captured image from the start of leaving the IRCF 2 a to the completion of leaving, the movement of the IRCF 2 a or the filter frame 2 c causes the “subject to move” Is falsely detected. Therefore, in order to eliminate this erroneous detection, the motion detection region is changed so that the luminance change region due to the movement of the IRCF 2a and the filter frame 2c is excluded from the motion detection region. Specifically, the counting of the time t after the start of leaving the IRCF2a is started (step S303). The video signal processing unit 6 switches to monochrome output processing (step S304).

  A region (area t1t2) in which IRCF2a and filter frame 2c move from time t1 to time t2 (movement time), where t1 and t2 (t2> t1) are the times of two captured images with different times for performing motion detection. ) Is obtained (step S305). Then, a motion detection area overlapping with the area t1t2 is obtained (step S306). This area t1t2 is a motion detection exclusion region, and includes not only a luminance change region due to the movement of the filter frame 2c but also a luminance change region due to the change from the IRCF 2a to the dummy glass 2b. Although details will be described later based on FIG. 4, FIG. 4 shows an example in which a plurality of motion detection areas can be set. Among the plurality of motion detection regions, a new motion detection region is set so as to exclude the region overlapping the area t1t2 from the motion detection region in the motion detection region obtained in step S306 (step S307). That is, if the area t1t2 is in the middle of the motion detection area, the areas on both sides of the area t1t2 become new motion detection areas. Steps S305 to S307 are repeated until the release of IRCF2a is completed. When the time for completion of removal comes (step S308), the count of time t is stopped (step S309), time t is cleared (step S310), and this control is performed. Exit.

FIG. 4 is a diagram illustrating the motion detection area change (steps S305 to S307) in more detail. Definitions of symbols in FIG. 4 are as follows.
Brightness change region coordinates (area t1t2) by the filter frame 2c from time t1 to t2
: (Xt1-W, 0) (Xt1-W, Lv) (Xt2, 0) (Xt2, Lv)
Area coordinates (area t1) of the filter frame 2c at time t1
: (Xt1-W, 0) (Xt1-W, Lv) (Xt1, 0) (Xt1, Lv)
Area coordinates of filter frame 2c at time t2 (area t2)
: (Xt2-W, 0) (Xt2-W, Lv) (Xt2, 0) (Xt2, Lv)
Xt1 (first X coordinate of the filter frame 2c at time t1)
: (Lh + W) × t1 / T
Xt2 (first X coordinate of the filter frame 2c at time t2)
: (Lh + W) × t2 / T
t1, t2: Imaging time of two captured images necessary for motion detection (t2> t1)
Lh: Number of horizontal pixels in the captured image area Lv: Number of vertical pixels in the captured image area T: Driving time of the IRCF 2a W: Number of pixels corresponding to the width of the filter frame 2c

  FIG. 4 will be described. FIG. 4A shows a captured image at time t1 after driving the IRCF 2a. The outermost square area is a captured image area 401. Two horizontally long rectangular areas in the captured image area 401 are motion detection areas 402 and 403. The vertically long rectangular area is the area of the filter frame 2c. The hatched portion on the right side of the filter frame 2c is the IRCF2a region, and the left side is the dummy glass 2b region. The IRCF 2a is about to leave the imaging optical path by moving from left to right in the figure. At this time, the subject vehicle exists at a certain position. The leading position in the traveling direction of the filter frame 2c is Xt1. The state changes from time t1 to time t2, and the captured image of FIG. 4B is captured.

  FIG. 4B is a captured image at time t2 (t2> t1) after driving the IRCF2a. The leading position in the traveling direction of the filter frame 2c is Xt2. At this time, the subject vehicle is also moving as indicated by the arrow. The motion detection unit 10 detects a motion by detecting a difference in luminance of the captured image between two frames having different times. Here, motion detection is performed from captured images at times t1 and t2.

  FIG. 4C is a diagram showing the presence or absence of a luminance change between frames when the captured image changes from FIG. 4A to FIG. 4B. Although two motion detection areas are set, the area 404 of the area t1t2 overlaps the motion detection area 403, and the motion detection area is changed to an area excluding the area 404 of the area t1t2 (motion detection area 403a). And 403b). The motion detection area 402 continues normal motion detection. As a result, the brightness of the area 404 in the area t1t2 is changed by the operation of the IRCF 2a, but is excluded from the motion detection area 403, so that the motion detection determination is not affected. Since there is no luminance change in the motion detection areas 403a and 403b, it is determined that there is no motion. In the motion detection area 402, it is determined that “there is motion” because there is a luminance change due to the movement of the subject vehicle. Therefore, the erroneous detection of the movement due to the separation of the IRCF 2a is not performed, and the area unrelated to the movement of the IRCF 2a can be correctly detected.

  In the present embodiment, the control when detaching the IRCF 2a has been described, but the same control is performed when the IRCF 2a is inserted. By controlling in this way, it is possible to eliminate erroneous detection of motion due to the operation of the IRCF 2a and the filter frame 2c when the IRCF 2a is inserted and removed, and it is possible to continue motion detection in a region where the operations of the IRCF 2a do not overlap. . FIG. 4 shows an example in which a plurality of motion detection areas can be set. However, it is obvious that the same can be considered when the entire display screen is a single motion detection area.

  In the above-described embodiment, the method using the luminance difference method for motion detection is described. However, it is obvious that the method can be used for another motion detection method such as a vector method. Although the present invention has been described in detail based on the preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. A part of the above-described embodiments may be appropriately combined.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.
The imaging device according to the present embodiment is a surveillance camera device in which the imaging lens 1 and the camera body (imaging device 4, photometry unit 8) are integrated, but the interchangeable lens (imaging lens 1) and camera body (imaging device 4, The present invention can also be applied to an imaging device in which the photometry unit 8) can be inserted and removed.

1: imaging lens, 2: filter switching unit, 2a: infrared cut filter, 2b: dummy glass, 2c: filter frame, 3: motor, 4: imaging element, 5: imaging signal processing unit, 6: video signal processing unit 7: Video signal output unit, 8: Photometry unit, 9: Filter control unit, 10: Motion detection unit, 11: Motion detection processing unit

Claims (13)

Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means;
A motion detection means for detecting a motion in a captured image obtained by the imaging means,
The image pickup apparatus according to claim 1, wherein the control means controls the movement detection means to stop motion detection while the wavelength band selection means is being inserted into and removed from the optical path by the insertion / removal means. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means;
A motion detection means for detecting a motion in a captured image obtained by the imaging means,
The image pickup apparatus according to claim 1, wherein the control unit performs control so as to change a motion determination criterion of the motion detection unit while the wavelength band selection unit is being inserted into and removed from the optical path by the insertion / removal unit.   3. The control unit according to claim 2, wherein, when changing the motion determination criterion, the control unit performs control so that the change region having the same size as the change region due to the movement of the wavelength band selection unit is excluded from the determination criterion. Imaging device.   The imaging apparatus according to claim 2, wherein when changing the movement determination criterion, the control unit performs control so that a change region of the same movement speed as the movement speed of the wavelength band selection unit is excluded from the determination criterion. . Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means;
A motion detection means for detecting a motion in a captured image obtained by the imaging means,
The image pickup apparatus according to claim 1, wherein the control unit controls the movement detection region of the movement detection unit to be changed while the wavelength band selection unit is being inserted into and removed from the optical path by the insertion / removal unit.   The imaging apparatus according to claim 5, wherein the control unit obtains a motion detection exclusion region from a movement speed and a movement time of the wavelength band selection unit when changing the motion detection region.   The imaging apparatus according to claim 5 or 6, wherein when the motion detection area is changed, the brightness change area depending on the presence / absence of the wavelength band selection means is also set as a motion detection exclusion area. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A control method for an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means stops motion detection of the motion detection means while the wavelength band selection means is being inserted / removed with respect to the optical path by the insertion / removal means. And a control method for the imaging apparatus. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A control method for an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
The control means for controlling the operation of the insertion / removal means based on the output of the photometry means changes the motion judgment standard of the motion detection means while the wavelength band selection means is being inserted into and removed from the optical path by the insertion / removal means. And a control method for the imaging apparatus. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A control method for an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
The control means for controlling the operation of the insertion / removal means based on the output of the photometry means changes the motion detection area of the motion detection means while the wavelength band selection means is being inserted into and removed from the optical path by the insertion / removal means. And a control method for the imaging apparatus. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A program for controlling an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means, and the movement detection of the movement detection means is stopped while the wavelength band selection means is being inserted into and removed from the optical path by the insertion / removal means. A program for causing a computer to function as control means for controlling to perform. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A program for controlling an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means, and the movement detection standard of the motion detection means is determined while the wavelength band selection means is being inserted / removed with respect to the optical path by the insertion / removal means. A program for causing a computer to function as control means for controlling to change. Imaging means for converting a subject image formed by the imaging optical system into an imaging signal;
A wavelength band selecting means for selecting a specific wavelength band from incident light on the optical path of the imaging optical system;
Insertion / removal means for inserting / removing the wavelength band selection means with respect to the optical path;
Photometric means for measuring the brightness of the captured image obtained by the imaging means;
A program for controlling an imaging apparatus comprising a motion detection means for detecting a motion in a captured image obtained by the imaging means,
Control means for controlling the operation of the insertion / removal means based on the output of the photometry means, and the motion detection area of the motion detection means is set while the wavelength band selection means is being inserted / removed with respect to the optical path by the insertion / removal means. A program for causing a computer to function as control means for controlling to change.

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